ERβ and Inflammation

Estrogen, through the regulation of cytokine production, can act both as pro-inflammatory and anti-inflammatory signals dependent on the tissue context. In breast cancer cells, ERα is known to modulate inflammatory signaling through interaction with NFκB. Whether ERβ has a role in inflammation is less explored. Low levels of ERβ have been corroborated in several immune-related organs and, for example, in colonic epithelial cells. Specifically, an impact of ERβ on colitis and colitis-associated colorectal cancer (CRC) is experimentally supported, using ERβ-selective agonists, full-body ERβ knockout mice and, most recently, intestinal epithelial-specific knockout mice. An intricate crosstalk between ERβ and TNFα/NFκB signaling in the colon is supported, and ERβ activation appears to reduce macrophage infiltration also during high fat diet (HFD)-induced colon inflammation. Finally, the gut microbiota plays a fundamental role in the pathogenesis of colitis and ERβ has been indicated to modulate the microbiota diversity during colitis and colitis-induced CRC. ERβ is thus proposed to protect against colitis, by modulating NFκB signaling, immune cell infiltration, and/or microbiota composition. Selective activation of ERβ may therefore constitute a suitable preventative approach for the treatment of for example colitis-associated CRC.